1. Field of the Invention
The present invention relates generally to catheters and more particularly to molded catheter distal ends, including molded multi-electrode distal ends, and other molded catheter distal end components and methods for the manufacture thereof.
2. Description of the Prior Art
Catheter distal end assemblies are currently manufactured in a tedious process that involves many steps and takes considerable time. Briefly, with regard to a multi-electrode catheter distal end assembly, a section of extruded polymer tube (the distal tube) is selected and the proximal end of the distal tube is expanded for joinder to the main body tube of a catheter. The polymer tube is then pierced in several places and a plurality of coil lead wires and thermocouple lead wires are threaded through the pierced holes. Anticipated locations on the distal tube for the plurality of coils are identified and one or more thermocouples are placed so as to be positioned under each coil. The thermocouples are then bonded to the distal tube in the specified locations. Thereafter, each coil is sequentially slid down the distal tube over the plurality of in-place thermocouples in a time consuming, precise process to avoid disturbing the thermocouples and lead wires as the coils are slid over them. The lead wires are particularly thin and fragile, and the inadvertent disconnection of even one lead wire results in an inoperative device. When properly positioned, the coil ends of each coil are covered with adhesive to bond them in place. Thereafter, a steering assembly is inserted through the distal tube and a tip electrode is soldered to the distal end of the steering assembly, and an electrical lead is attached to the tip electrode. The proximal end of the distal tube is then joined to the main catheter body.
The present invention includes a catheter having a molded distal end assembly that includes at least one component. In a preferred embodiment, the catheter end component includes one or more electrodes that are molded into the walls of the assembly. In an ablation type electrode assembly, one or more temperature sensors may be associated with an electrode. In manufacturing this multi-electrode end assembly, lead wires from the coils and temperature sensors are preferably spiral wound and molded into the walls of the assembly to reduce the possibility that the lead wires may become disconnected during manufacturing or later during use of the catheter, and also to increase the flexibility of the distal end assembly. Particular core pin designs with mold blocking techniques are utilized to mold the coils and lead wires into the wall of the end assembly. Specific embodiments of the molding method include separate distal end assemblies, integrally molded distal end assemblies and molded components of catheter end assemblies.
It is an advantage of the molded distal end assembly of the present invention that it has a smooth outer surface.
It is an advantage of some of the molded multi-electrode distal end assemblies of the present invention that they have a smooth surface at the edges of the electrodes and between the electrodes.
It is a further advantage of the molded multi-electrode distal end assembly of the present invention that it has a unitary outer surface that eliminates the possibility for blood ingress into the catheter lumen.
It is yet another advantage of the molded multi-electrode distal end assembly of the present invention that the electrode leads are molded in place, to reduce the possibility of disconnection during device usage.
It is yet a further advantage of the molded multi-electrode distal end assembly of the present invention that electrodes can be more accurately and closely spaced along the assembly body.
It is still another advantage of the molded multi-electrode distal end assembly of the present invention that the temperature sensors are bonded to the electrodes, thus providing a reliable feedback reading.
It is an advantage of the unitary, molded catheter assembly which includes a molded multi-electrode distal end assembly of the present invention that the molding of the multi-electrode assembly to the main catheter body tubing eliminates a difficult-to-make joint.
It is another advantage of the unitary, molded multi-electrode catheter assembly of the present invention that the main catheter body, the steering assembly, the tip electrode and the multi-electrode assembly are all molded together to form a single bonded unit.
It is an advantage of the manufacturing method for the molded distal end assembly of the present invention that it is easier, faster and less expensive than the prior art methods by eliminating many manual steps.
It is an advantage of the manufacturing method for the unitary, molded catheter assembly of the present invention that in one molding step, the steering assembly and tip electrode are joined with the multi-electrode assembly.
These and other features and advantages of the present invention will become understood by those skilled in the art upon reading the following detailed description and claims.